1. Technical Field
The present invention relates to an electronic device. Particularly, the present invention relates to an electronic device including a circuit board which includes a plurality of dielectric layers and has a surface having a hollow into which an electronic component is placed.
2. Related Art
As a multilayer substrate in which a plurality of substrates each of which has a pattern wiring are stacked, a multilayer substrate has been known as disclosed, for example, in Japanese Patent Application Publication No. 2007-88058. In such multilayer substrate, sometimes an electronic component is disposed in a concave portion which is formed by removing a dielectric layer as the surface of the multilayer substrate by means of machining. In this case, the electronic component disposed in the concave portion is electrically connected to a pattern wiring formed on a side surface of the concave portion through a wire, for example.
In such multilayer substrate, radio emission is generated from the wire connecting the electronic component to the pattern wiring when a high frequency signal is transmitted from the pattern wiring to the electronic component. Such radio emission sometimes has an effect on a signal transmitted through the other wire or the pattern wiring. Particularly, when an attenuator is disposed as the electronic component, it is expected that the attenuation ratio of input/output of the attenuator is affected.